Cooling System Flush....Problems

[jackasti]

Hi Techno-Gods,
While my Bongo 2.5 TD has been performing faultlessly for the past year I have been alarmed at the continuing horror stories of cylinder head failures. To this end I placed the van in the hands of a bongo expert for a complete cooling system flush and replacement of the antifreeze. Last changed 2 years ago.

Following this service I noted that the cooling fans seemed to be on whenever I stopped, the engine"smelt" hot and there was a slight rise in the dash temperature guage.. No loss of coolant.

On return to the mechanic the engine temp measurement showed No 1 cylinder was 83, No2 was 91, No 3 was 95 and No 4 was 102. where I believe they should all be about 75-80. Following a re-bleed and a short run all the temperatures rose further

The Thermostat temp was normal normal. However the coolant at bleeding was very brown with no evidence of antifreeze however hydrometer showed -15 deg c protection

The van remains with the mechanic who intends to reflush the system under the assumption that there is a blackage in the cylinderhead waterway, caused by the flushing dislodging "stuff". He is hoping that once the reflushing has been carried out that the cooling fans will not trip in unessessarily but tells me that" flushing the cooling system often causes problems...........

Not being a guy familiar with a spanner is there anything else I should be pointing the mechanic to? Could the cylinderhead waterways be perminantly blocked by flushed debris?

Any guidance would be most appreciated

[daveblueozzie]

Have you changed the thermostat ?
if not that's a good place to start, and make sure you get a genuine Mazda stat about £18, not a cheapo one from the Internet.

[jackasti]

No. The mechanic informed me that as the hoses were on, temperature wise, that it was not required. Also that the thermostat was difficult to get at.

[francophile1947]

Judging by the brown coolant, it does sound as if the flushing has disturbed some crud in the system. Hopefully a re-flush will clear it

[dobby]

Mine overheated in 2006, meaning all the crud and junk spread around the system. Also, the rad either got or was blocked. It ran hotter thereafter and the head went in 2009. With hindsight I'd have replaced the stat, had the rad properly flushed out and replaced the hoses or anything else that was needed. A few hundred pounds might have saved £1000+ later.

Also, consider fitting an LCA and Mason alarms or Haydn's latest arrangements.

Hope it's all sorted.

Best of luck

[Kincaid]

Have you changed the thermostat ?
if not that's a good place to start, and make sure you get a genuine Mazda stat about £18, not a cheapo one from the Internet.

Would the BLUEPRINT thermostats compare to the Mazda ones? I'm asking as the original Mazda ones seem to have been out of stock in the Fury shop for some time and I'm thinking I may need to take the BLUEPRINT one.

[jackasti]

Hi
Just ordered one from Japanese Automotive Solutions (JAS). Genuine Mazda part. Cost £19.91 then £3.50 postage. total £23.41.

Phone: 0845 6808 007
email: www.japautosolutions.com

Colin

[daveblueozzie]

Have you changed the thermostat ?
if not that's a good place to start, and make sure you get a genuine Mazda stat about £18, not a cheapo one from the Internet.

Would the BLUEPRINT thermostats compare to the Mazda ones? I'm asking as the original Mazda ones seem to have been out of stock in the Fury shop for some time and I'm thinking I may need to take the BLUEPRINT one.

i went to my local Mazda dealer, they ordered me one, got it a couple of days later, they knew what a bongo was and which stat to order.

[stuc]

just changed the heater matrix and the stat. the stat is hard to get at but an able mechanic should find it easy enough. The stat work was all done from underneath on a 2 post ramp by myself. i am a spraypainter not a mechanic and i managed. didnt have any bleeding problems.

[widdowson2008]

Bought a stat yesterday from Mazda - Chesterfield.
Gave them the part number KL0115171A and they pulled one from stock. The real thing.
Cost £15.80 + VAT

The difference between Mazda and Blueprint stats is the stem seal (Blueprint doesn't have one).
For the price difference, not worth geting a copy in my opinion.

[Ian]

Have you changed the thermostat ?
if not that's a good place to start, and make sure you get a genuine Mazda stat about £18, not a cheapo one from the Internet.

Would the BLUEPRINT thermostats compare to the Mazda ones? I'm asking as the original Mazda ones seem to have been out of stock in the Fury shop for some time and I'm thinking I may need to take the BLUEPRINT one.

Now back in stock. Supply line problems from Japan.

[Bob]

Have you changed the thermostat ?
if not that's a good place to start, and make sure you get a genuine Mazda stat about £18, not a cheapo one from the Internet.

Would the BLUEPRINT thermostats compare to the Mazda ones? I'm asking as the original Mazda ones seem to have been out of stock in the Fury shop for some time and I'm thinking I may need to take the BLUEPRINT one.

Now back in stock. Supply line problems from Japan.[/quote]


Why's that then?

[lazyb5]

Hi Jack
Sounds like your mechanic needs to remove the Thermostat and put the hose pipe in the top hose and flush until the outlet runs clear may take a few mins. The Thermostat is 2 bolts then it drops out. I would get a low coolant alarm, and a engine temp alarm both help see what the engine is doing. I`m around the Spalding area and we are at West Runton for 3 days at the Camping and caravan club on the 11th- 13th April we could call back your way to help if you still have probs. You could Pm if needed not a veteran but have bled the bongo twice now and it took about 35-40 mins both times. Is he following the correct procedure?

[Northern Bongolow]

if there has been a flush in the system please make sure you remove the rear heater pipes under the offside rear when the system is rinsed clean,as all the solids that have been disturbed settle in the lowest point, namely the rear heater matrix.
i would remove the top hose and the stat and back flush the head/block too.

i would get your mechanic to watch the bleeding a mazda bongo video's on youtube.

[jackasti]

Many thanks for all of your advice and guidance.
New Mazda thermostat is on its way. Low coolant alarm already fitted to calm my paranoia.

The mechanic is " A Good un" and hopefully the second flush and a good sound bit of agressive counselling to the cylinder head will do the trick.

Failing that.................?